Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth companyx

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.x

Effective January 31, 2018, Robert Perez resigned as a director of Flex Pharma, Inc. (the “Company”). Mr. Perez's resignation from the Company's Board of Directors and Compensation Committee of the Board of Directors did not result from any disagreement with the Company and was a result of Mr. Perez's desire to pursue other interests.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.